Emulsion fuel is an unconventional fuel for diesel engines, which can be used without modifications in the engine. The benefits of an emulsion fuel include lowering the emissions of nitrogen oxides (NO x ) and particulate matter (PM) which are harmful to health and cause diesel engines to suffer. This paper explains in detail the effect of water in the emulsion fuel on the emissions of NO x , PM, carbon monoxide (CO), hydrocarbon (HC), smoke and exhaust temperature. Experimental results from various researchers show a decrease in the NO x and PM emissions simultaneously. However, the results with the increasing water percentage in emulsion fuel are not consistent for HC and CO emissions. The water content in emulsion fuel affects the combustion and reduces the peak temperature in the combustion chamber. On the other hand, microexplosion phenomenon occurs and causes an increase in the volatility of diesel fuel which improves the combustion efficiency.

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In this study, the effect of load on the tribological performance of RBD palm olein is investigated using a four-ball wear tester according to the standard test of ASTM D4172. Tests were conducted with 40, 60, 80, 100 and 120 kg normal loads. The experimental temperature and rotational speed were held constant at 75 °C and 1200 rpm, respectively. The test duration was 60 minutes in all cases. For each load, the tribological properties of RBD palm olein were compared with the properties of additive-free paraffinic mineral oil. The results focused on the frictional torque, wear scar diameter, friction coefficient and the flash temperature. Following the completion of the wear test experiments, the ball wear condition and lubricant properties were observed. These results show that RBD palm olein has a lower coefficient of friction than paraffinic mineral oil; however showed a high oxidation effect under high temperature work conditions.

In this work, based on the optimal control theory approach, a four-wheel-active steering (4WAS) system is proposed for low speed and high speed applications. A model following the control structure is adopted consisting of a feed-forward and feedback compensation strategy that serves as correction inputs to enhance the vehicle's dynamic behavior. The velocity dependent feed-forward control inputs are based on the driver's steering intention while the feedback control inputs are based on the vehicle's state feedback errors, being the sideslip and yaw rate of the vehicle. Numerical simulations are conducted using the Matlab/Simulink platform to evaluate the control system's performance. The performance of the 4WAS controller is tested in two designated open loop tests, being the constant steer and the lane change maneuver, to evaluate its effectiveness. A comparison with conventional passive front-wheel-steering (FWS) and conventional four-wheel-steering (4WS) systems shows the preeminent result performance of the proposed control strategy in terms of the response tracking capability and versatility of the controller to adapt to the system's speed environment. In high speed maneuvers, the improvement in terms of yaw rate tracking error in rms is evaluated and the proposed active steering system considerably beat the other two structures with 0.2% normalized error compared to the desired yaw rate response. Meanwhile, in low speed, turning radius reductions of 25% and 50% with respect to the capability of normal or typical FWS vehicles are successfully achieved.

This study investigates the physical properties of pure palm fatty acid distillate (PFAD) as a new, clean and renewable source of lubricant and hydraulic oil. This study is done using a four-ball tribotester. The experiments are conducted at five different temperatures of 55, 75, 95, 105 and 125 °C. The rotational speed was fixed at 1200 rpm, normal load was 40 kg and duration was 1 hour. For evaluating the results, all experiments again were conducted using commercial engine mineral and hydraulic mineral oil and at the end all results were compared together. The results show that PFAD has higher anti friction and anti-wear ability.